In recent years, in a light emitting display device for mobile purposes, there is a strong demand for high resolution and low power consumption. Display devices which use a liquid crystal display device (LCD) or organic light-emitting diode (OLED) such an organic EL display device or electronic paper etc are being adopted as display devices for mobile purposes.
Among these, an organic EL display device or electronic paper do not require a back light or polarizing plate which were necessary in liquid crystal devices. Furthermore, since the drive voltage of a light emitting element is low, these devices are attracting a great deal of attention as low power consumption and thin light emitting display device. In addition, since it is possible to form a display device just with a thin film, it is possible to realize a display device capable of bending (flexible). Furthermore, since these display devices do not use a glass substrate, they are attracting a great deal of attention as display devices which are light and difficult to break.
A light emitting element such as an organic EL element arranged in each pixel of an organic EL display device is known to have a light emitting efficiency which drops due to degradation when exposed to oxygen or a water component. In order to solve this problem, a technology for forming a seal member so as to completely enclose the periphery of a light emitting element and fill a resin material as a filling material into a region enclosed by two opposing substrates and the seal member thereby controlling oxygen and a water component from entering from the exterior is disclosed in Japanese Laid Open Patent 2011-113808 for example.
In addition, a flexible substrate is used in a flexible display device. Although it is possible to use a very thin film of about 10 um as the flexible substrate, a stand-alone thin film flexible substrate warps due to internal stress.
When the flexible substrate in the structure shown in Japanese Laid Open Patent 2011-113808 is used, each opposing substrate is not fixed further to the exterior than a seal member. Therefore, warping occurs further to the exterior than a seal member in each opposing substrate due to internal stress. A problem wherein a substrate and a seal member peel occurs when force in the direction where the substrate and the seal member are peeled continues to operate on an end part of the seal member due to this warping. When the substrate and the seal member peel away from each other, not only is there a loss in a clean look appearance, the stopping ability drops with respect to oxygen or water component from the exterior which causes degradation of a light emitting element. As a result, there is a drop in reliability of the display device. In addition, when a peeling state becomes even worse, the substrate and the seal member become completely peeled from each other the image display itself of a display device may be badly affected.
In addition, the display device shown in Japanese Laid Open Patent 2011-113808 has a structure in which a seal member and filling material are formed for each display device. When a dip method or inkjet method is used for forming a seal member, this requires not only time for forming a seal member pattern but time is also necessary for obtaining alignment with respect to a substrate formed with the seal member. That is, in a structure where the seal member and substrate are formed in each display device respectively, productivity becomes poor and leads to problems such as lengthening of the manufacturing process and an increase in manufacturing costs.